Prior art of interest which affords background to the invention to be described and illustrated includes the following United States patents:
U.S. Pat. No. 2,633,028 discloses electronic devices which utilize capacity signals derived from the relative positioning of components.
U.S. Pat. No. 2,935,681 is of interest in that it reveals a proximity device designed to probe the surface contour of an object and employs variation in the capacitance of circuitry to accomplish same.
Still another U.S. Pat. No. 3,772,685 reveals detection mechanisms responsive to the capacitance established by the human body but limited to employing liquid crystal cells.
U.S. Pat. No. 3,787,732 employs an electronic switching device operated by human touch. According to this disclosure however it is the resistance offered by the skin as opposed to capacitance, that is the significant concern.
Finally U.S. Pat. No. 3,879,618 outlines a human touch sensitive device but like latter mentioned U.S. Pat. No. 3,787,732 utilizes resistance introduced by human touch to trigger the signal.